Uniformity Coefficient Research Articles

Proxy model of constant-rate mercury intrusion experiment for low-permeability reservoir based on meta-learning

Pore structure parameters are used to characterize the reservoir pore structure and are crucial for evaluating and developing reservoirs for low-permeability reservoirs. However, traditional experiments to obtain pore structure parameters such as constant-rate mercury injection (CMI) can be time-consuming and expensive. To reduce the cost of obtaining these parameters, this study proposes using meta-learning as a proxy model for CMI experiments. We developed six meta-learning models: gray wolf optimizer extreme learning machine, whale optimization algorithm extreme learning machine (WOA-ELM), moth-flame optimization extreme learning machine, gray wolf optimizer support vector regression, whale optimization algorithm support vector regression, and moth-flame optimization support vector regression. These models were used as proxies for CMI and trained with conventional and experimental rock data to predict porous structure parameters such as average throat radius (ATR), maximum throat radius, variance, relative sorting coefficient (RSC), and uniformity coefficient. We compared our models with ten conventional proxy models. The results indicate that the WOA-ELM achieved the best performance, with an R2 (R-squared) of 90.1%, a mean absolute error of 0.4522, and a root mean square error of 0.3852. Compared to conventional models, this represents an improvement in R2 of 14.66%–30.46%. The meta-learning models also achieved the highest prediction accuracy in average throat radius (with R2 up to 96.58%) and showed an improvement (with R2 up to 91.21%) in relative sorting coefficient and uniformity coefficient, indicating the advantages of the meta-learning model in the prediction of pore homogeneity.

Agricultural spray drone deposition, Part 2: Operational height and nozzle influence pattern uniformity, drift, and weed control

Abstract Agricultural spray drone (ASD) use in managed turfgrass has been given limited attention in the scientific literature. Further, deposition patterns of ASD spray have been obscured in previous research by ambient wind, crop canopy interference, and limited sampling resolution. Using a continuous sampling method involving blue colorant and water sprayed over white Kraft paper that was assessed via digital image analysis of stain objects and referenced spectrophotometric analysis of extractant, deposition metrics were estimated across a 29.3-m transect perpendicular to an ASD or ground sprayer spray swath. The ASD applies very fine droplets that are highly concentrated with herbicide, similar to ultra-low volume treatments, that improved smooth crabgrass [Digitaria ischemum (Schreb.) Schreb. ex Muhl.] control compared to a ground sprayer when the ASD was operated at 2 m above the turf. Unfortunately, these very fine droplets also drift, leading to four times greater droplet density at distance of almost 12 m away from the targeted spray swath following an operational height of 10 m compared to that at 2 m. As ASD operational height increases, drift and effective swath width at 30% coefficient of variation uniformity increases while effective application rate, total deposition, and D. ischemum control by quinclorac herbicide decreased. Total deposition decreased 6% for each m increase in ASD operational height, likely due to evaporation. The potential losses due to evaporation is a serious consideration for ASD use that has received little attention in the scientific literature. Our data suggest that ASD operational height should be as low as possible, but modification of spray systems may be needed to improve homogeneity of spray pattern.

Enhancing hydraulic efficiency in jet impingement sprinklers: Comparative analysis of aperture ratios compared with non-impingement sprinklers

A jet impingement sprinkler was designed based on asymmetric collision between the primary and secondary jets to replace traditional rotating sprinklers that require additional water distribution devices to provide suitable water distribution at low pressures. The study focuses on the ratio of apertures between primary and secondary nozzles, deriving a theoretical relationship based on jet momentum. The factors contributing to the variation in hydraulic performance between jet-impingement and non-impinging sprinklers are elucidated by combining hydraulic performance experiments with experiments using high-speed photography (HSP). The results show that the developed jet impingement sprinkler achieved a smoother water distribution trend. The wetted radius and Christiansen's uniformity coefficient of the jet impingement sprinkler were evaluated using the Criteria Importance via the Intercriteria Correlation (CRITIC) method. A comparison of the average scores shows that an aperture ratio of 1.66 performs best under full pressure. By contrast, an aperture ratio of 1.33 exhibited superior performance at low pressure. Jet deflection angle and jet breakup length were obtained through HSP experiments. The relative error between the measured and theoretical jet deflection angles was less than 5%, demonstrating the reliability of the proposed theoretical calculation method. A non-linear curve was used to establish the relationship among the aperture ratio, diameter of the primary nozzle exit, jet breakup length, average measured jet deflection angle, working pressure, and wetted radius. The relative error between the calculated and measured values was within 4%, indicating the suitability of the new formula for calculating the wetted radius of jet impingement sprinklers.

The Application of Smart Drip Irrigation System for Precision Farming

Managing water resources in urban areas is relatively expensive due to the costs of electricity and water distribution from wells and water companies. Therefore, water resource management for urban agricultural purposes needs to be made efficient, such as through smart irrigation technologies, one of which is the drip irrigation system that engages soil moisture sensors and the Internet of Things (IoT) to control the amount of distributed water. This study aims to apply and evaluate the performance of a drip irrigation system based on soil moisture sensors and IoT in urban agriculture. The results showed that the distribution uniformity in the system was identified at fair levels, with a Coefficient of Uniformity (CU) of 90.15% and 86.58%, respectively. Furthermore, our study also found that the IoT-assisted drip irrigation system that engaged a Deep Neural Networks (DNN) model to meet the water requirement led to better peanut yield than the irrigation system based on soil moisture as a control.

Effect of Grain Size and Porosity/Binder Index on the Unconfined Compressive Strength, Stiffness and Microstructure of Cemented Colombian Sands.

Artificial cementation of granular soils results in improved stabilization, increased stiffness, and greater mechanical strength. The porosity index and volumetric cement content η/Civa is presented as a key measure to study the evolution of different soil stabilization types. However, this index had not been previously studied or adjusted for sands in Colombia. Therefore, this study evaluates the applicability of the η/Civa index on unconfined compressive strength (qu) and stiffness (Go), complemented by microstructural analysis, in four sandy soils from Luruaco (Atlántico), Lorica (Córdoba), Medellín (Antioquia), and Bogotá D.C. The soils were stabilized with Type III Portland cement in dosages of 3%, 5%, 7%, and 9%, and subjected to UCS, ultrasound, and SEM-EDS tests after a curing period of 7 days. It was found that increasing cement content results in higher qu values for the samples, and higher molding density also leads to higher qu values. Additionally, the grain size distribution influenced the adjustment of parameter "a". In the sands from Bogotá and Lorica, with high uniformity, the value of "a" was 1.00. In contrast, mineralogy and particle shape played a predominant role in the sands from Medellín and Luruaco, where the coefficient of uniformity is higher, suggesting a possible inverse relationship between particle angularity and the value of "a".

Factors influencing static and cyclic behaviour of polymer-grouted sands

ABSTRACT In this study, thorough laboratory research was conducted in order to increase knowledge of the beneficial effect of water-soluble epoxy resin on the monotonic or cyclic triaxial strength of different sands. Seven sand fractions (with different particle sizes, uniformity coefficients and mineralogical compositions) were injected with solutions of epoxy resin and water, at ratios of 3.0, 2.0 and 1.5. To evaluate the influence of chemical treatment on the static strength behaviour of grouted sands, a series of monotonic triaxial tests on dry specimens and isotropically consolidated undrained (CIU) triaxial tests, were conducted on samples cured for 90 days. CIU cyclic triaxial compression tests were also performed, to assess improvements in the cyclic resistance of treated sands. The experiments showed that this resinous grouting resulted in an appreciable increase in cohesion values, particularly for fine sands and well-graded sands, ranging from 0.15 to 0.66 MPa. Despite the fact that friction angle values were reduced, the overall shear strength increased over a wide range of stresses. Moreover, all grouted sands exhibited a substantial improvement in cyclic properties, with failure occurring at significantly elevated stress levels and after enduring a larger number of loading cycles, compared to their untreated counterparts.

Multi-objective optimization towards cooling performance of teardrop section Kagome trusses array jet impingement composite cooling structure with cross-flow

Teardrop Section Kagome trusses array can be a spoiler for a new generation of advanced combustion chambers. In this study, multi-objective optimizations are applied to optimize a jet impingement composite cooling structure with cross-flow. Four structural parameters with five levels and three performance parameters are calculated in design of experiment and fitted by response surface methodology. The database is expanded by non-dominated sorting genetic algorithm-II, and then technique for order preference by similarity to an ideal solution is used to calculate the optimal structures under different operating conditions by different weights of the performance parameter. The conclusions are as follows: The minimal Equality of variances and fitting accuracy are 35.4371 and 93.6%. Diameter of the cross-section has the largest positive main effect on average Nusselt number and pressure loss coefficient, while angle between the rod and the horizontal plane has the largest positive effect on temperature uniformity coefficient. The interaction of trailing edge angle with angle between the front rod and the back rod in the horizontal plane is large. Case15 is chosen, where the weight ratio is 1:5:5, improvement of the corresponding optimized performance parameters of the simulation results with respect to the Origin of three performance parameters are 26.72%, −2.93%, 91.59% respectively. It provides a feasible reference for future advanced combustion chambers and accelerates their development process.

Effect of aggregate size on the slump and uniaxial compressive strength of concrete: a DEM study

The aggregate size and particle-size distribution (PSD) can change the packing density, slump, and strength of concrete. The micromechanical effects of aggregate size on the slump and strength remain unclear. The current numerical study examined concrete behavior using slump and uniaxial compressive strength (UCS) tests considering the aggregate size distribution using the discrete element method. The effect of the aggregate size on the packing density, UCS, and slump of the concrete was analyzed. To accomplish this, we evaluated how variations in the uniformity and curvature coefficients of the PSD, as well as the specific surface area of the samples, were affected by changes in aggregate size. Although the simulations were based on standard specimens from the laboratory, the results showed good agreement with the documented experimental results. Briefly, at a 40–60% fine aggregate content, the packing density and compressive strength of the concrete reached their peaks and caused a decrease in the height of the slump. The uniformity and curvature coefficients did not influence the slump height. The induced shear band could be tracked during the UCS tests and the crack angles could be measured. At the optimum fine content (40–60%), the shear bands were primarily localized and propagated through the samples having different fine contents.

Impact of Different Drip Emitter Types on Hydraulic Performance and Wetted Zone Characteristics in Okra Cultivation

Drip irrigation system is the most efficient and economical method for irrigation vegetable production. The study aimed to design and evaluate the hydraulic performance of three different types of emitter namely Regular gauge (RG), Compensating pressure (CP) and non-compensating pressure (NCP) using okra as a test of a crop. This study was conducted at the experimental farm of the Faculty of Agricultural Science, Zamzam University in 2023. The treatments were laid out in a randomized complete block design (RCBD) with three replications. Parameters of hydraulic performance of drip emitters were average discharge (Qavg %), discharge variation (Qvar), coefficient uniformity (CU %), coefficient of manufacture variation (CV), emission uniformity (EU %) and statistical uniformity (US %). The results showed that the values of (CU%), (CV), (EU%), (US%) and percentage emitters clogging (Pclog%) were 99.52%, 0.49, 68.01%, 74.14%, 2.8% and 99.32%, 0.36, 52.06%, 63.47%, 1.65% and 99.09%, 0.26, 40.07%, 51.05%, 0.85% for non-compensating pressure (NCP), compensating pressure (CP) and regular gauge (RG respectively. It is considered coefficient uniformity (CU %), was good and found to be within the excellent range while discharge variation (Qvar) was found to be within the desirable range, emission uniformity (EU %), coefficient of manufacture variation (CV), and statistical uniformity (Us %) were found to be within the range of poor, low, acceptable and unacceptable. Thus, the study recommended the best type of emitter was regular gauge (RG), because it has the highest crop yield and water productivity as compared to other emitters, non-compensating pressure emitters (NCP) and compensating pressure emitters (CP)

Predictive model for shear wave velocity of gravelly soil and its application to liquefaction triggering assessment

Several studies have established empirical correlations between shear wave velocity (Vs) and standard penetration test blow count (SPT-N) for engineering use. However, these empirical correlations cannot be applied to gravel-rich soils since the measured SPT-N is often inflated in gravel. Therefore, an empirical correlation of Vs for gravel is developed in this study using the Engineering Geological Database for the Taiwan Strong Motion Instrumentation Program. The Vs predictive model considers gravel content (GC) and coefficient of uniformity (Cu) in addition to effective vertical stress, void ratio, fines content, plasticity index, and overconsolidation ratio, which have been considered previously. The proposed model indicates that Vs increases with GC and Cu. Moreover, the Vs adjusted for GC can be used with existing Vs -based liquefaction triggering relationships to rationally define the boundary between liquefaction and non-liquefaction case histories with different GCs.

Influence of dispersion of a new type whole crystals seed on crystallization process and sugar quality

The aim of the work was to study effectiveness of the influence of a new type crystal seed with different microcrystals dispersion on the process of sucrose crystallization and sugar quality. The dispersion of microcrystals of the crystal-forming agent with whole crystals was determined and curves of their differential distribution were presented, which showed the average particle sizes of the “Ester K 01” are 18.2 μm and 46.4 μm. The morphological characteristics were determined of particles of the whole crystals seed and the seed slurry produced at a sugar factory. The duration of massecuite boiling was investigated and a comparative characterization of the quality indicators of the resulting massecuite, mother liquor, and sugar was given depending on the use of the whole crystals seed with different dispersion of microcrystals in comparison with the factory slurry. Microphotographs of sugar crystals in the massecuite were obtained with their size recorded 5, 10 and 20 min after the input of various seeds. The morphology of sugar crystals was studied in the finished massecuite. A comparison is given of the granulometric composition of sugar crystals obtained with crystal-forming agents with different dispersion. It was found based on the results of the study that when using the “Ester K 01” (46.4 μm) in thick juice with high turbidity the corresponding crystals are formed faster in the total amount of the massecuite. It was also found that there is a kind of blocking of the process of adjacent growth of crystals from the particles of impurities of thick juice with high turbidity. This contributes to the formation of more uniform, homogeneous crystals of the correct shape. The results are presented in the article of tests of the whole crystal seed “Ester K 01” (18.2 μm) and “Ester K 01” (46.4 μm) at sugar factories using the method of working on the seed magma and the method of shock crystallization respectively. The dependences were obtained of the average linear size, the amount of sugar of the 0.65 mm fraction, the coefficient of variation and the coefficient of uniformity of sugar crystals on the consumption of the whole crystals seed “Ester K 01” (crystal size 46.4 μm). The regression equation was developed in natural form for the process of sucrose shock crystallization. It was established the rational consumption of the crystal-forming agent “Ester K 01” (crystal size 46.4 μm), which ensures the effective crystallization of sucrose for the process of crystallization by the shock induced method.

Flexural & Compressive Strength Behaviour of Lowweight Engineered Timber Slab(ETS) composed of crack filler, wood adhesive & Saw dust

This study presents the Compressive & Flexural Strength performance of Low-weight Engineered Timber Slab(ETS) composed of wood adhesive, Saw dust, & crack filler. It provides empirical data on the flexural and compressive properties of engineered timber slab(ETS), which is an element of wood adhesive(WA), sawdust(SD), crack filler(CF). SD gave values of 562.3/m3, 0.67, 39.66%, 2.85, 1.2 and 2.98 for mean bulk density, mean specific gravity, mean water absorption, finess modulus, coefficient of curvature (Cc) and uniformity (Cu). Batching was done by volume by virtue of the low density of the component materials (SD & CF). The component materials were manually mixed. A total of twelve (12) cubes of size 150 x 150 x 150mm, were produced from mix ratios 0.5:0.5:2 & 0.5:0.75:2(WA : CF : SD) for compressive strength test. The above mix ratios were adopted based on the light-weight nature & high rate of water absorption of the component materials. A total of Twenty (20) slabs of size 300 x 300 x 100mm, 300 x 300 x 125mm, 300 x 300 x 150mm, 300 x 300 x 175mm and 300 x 300 x 200mm were cast for flexural strength of slab. Twenty(20) slabs were produced for with slab thickness of 100mm, 125mm, 150mm, 175mm and 200mm using the mix ratios 0.5:0.5:2 & 0.5:0.75:2(WA:CF:SD) respectively. the mean values of the compressive strength, flexural strength and deflection were 14.9MPa & 15.78MPa, 5.06MPa to 5.52MPa and 28.9mm to 86.5mm respectively

Estimating the compacted dry density of gravelly soil with oversized particles

The compacted dry density of gravelly soils containing particles that are too large for ordinary laboratory compaction tests is usually estimated by measuring the dry density of the base sample obtained by removing over-sized particles then correcting the measured value by the Walker-Holtz Equation (W&H Eq.). It is known that the W&H Eq. overestimates the dry density of gravelly soils and this trend becomes stronger as the mass ratio P of oversized particles increases. It seems that a satisfactory solution is not yet available. A comprehensive series of laboratory compaction tests was performed on a wide variety of gravelly soil samples with different particle sizes, grading uniformities and particle shapes. The followings were found. The ratio, X, of the maximum dry density predicted by the W&H Eq. to the measured value increases linearly from unity as P increases from zero up to approximately 0.75. The slope of the X-P relation, (X − 1.0) / P, increases as the coefficient of uniformity or the fines content of the base sample increases and as the gravel particles become more angular in a synergistic manner. It is proposed to estimate the maximum dry density of compacted gravelly soil containing oversized particles by dividing the value predicted from the W&H Eq. by X obtained from the substitution of P into the relevant X-P relation. Proposed based on the above is an effective and efficient compaction method for gravelly soils containing oversized particles that controls the degree of saturation and the compaction energy.

Prediction of moisture content of cement-stabilized earth blocks using soil characteristics, cement content, and ultrasonic pulse velocity

This article investigates the importance of moisture content in cement-stabilized earth blocks (CSEBs) and explores methods for their prediction using machine learning. A key aspect of the research is the development of accurate moisture content prediction models. The study compares the performance of various machine learning models, and XGBoost emerges as the most promising model, demonstrating superior accuracy in predicting moisture content based on factors like soil properties, cement content, and ultrasonic pulse velocity (UPV). The study employs SHAP (SHapley Additive exPlanations) to understand how these features influence the model’s predictions. UPV is the most significant factor affecting predicted moisture content, followed by cement content and soil properties like uniformity coefficient. Also, the study explores the possibility of using a reduced set of features for moisture content prediction. They demonstrate that a combination of UPV, cement content, and uniformity coefficient can achieve good accuracy, highlighting the potential for practical applications where obtaining all data points might be challenging.

Local and Low-Cost Filter Media of Simple Water Filtration

Commonly the Installation of a Drinking Water Supply System (SPAM) in Indonesia consists of Coagulation-Flocculation, Sedimentation, Filtration and Disinfection Processes as a complete Process Unit for surface feed water such as rivers or lakes. Similarly, the clean water treatment process in Banjarbaru, South Kalimantan, Indonesia uses intake water sources from irrigation. The intake water from irrigation used by the local Regional Drinking Water Company has good quality with a low turbidity value below the quality standards set by the central government. Based on these qualities, the right process unit to treat the water is by filtration only. Therefore, it is necessary to conduct evaluation and research to improve the efficiency of the process unit and the economic value of the water treatment. The purpose of this study is to investigate and evaluate irrigation feed water treatment by filtration using local and low-cost filter media. The filter reactor is designed with a rapid media filter type. The media is characterized using energy dispersive X-ray spectroscopy (EDS) and a scanning electron microscope (SEM) which is plugged in with EDS to find out the primary constituents and morphological information and after knowing the characterization of the media, and followed by tested the media placed in the water filter reactor with data collection. The results show that the size of the filter media has great effect on the quality of the processing water, which the smaller the media diameter conducted high selectivity and speed up filtration time. The greatest result obtained from testing feed water with media is 87.64%. Turbidity of the feed water sample process, which was previously 0.34 NTU, could be decreased to 0.02 NTU. Effective size of 0.4 mm and uniformity coefficient of 1.35 mm are the optimal allowable values.

Combination of control factors influencing application uniformity of a low-pressure pivot sprinkler spray unit

The objective of any pivot irrigation system is to ensure uniformity of application of water which can be achieved when responsible factors such as pressure, drop tube lengths, nozzle size etc. are adequately designed. This indoor experiment conducted in a 44m2 laboratory facility tends to evaluate the extent of the influence of some sprinkler design parameters on the performance of a low pressure single pivot sprinkler spay unit. The parameters considered are; pressures of 9,12, 15 and 19Psi, nozzle sizes of 4.17, 5.56, 6.95 and 8.14 mm and drop tube lengths of 1, 1.2 and 1.5m. In this experiment an inverted U-shaped frame designed to support a spray sprinkler at different heights was used. The hydraulic installation with manual throttle valves for controlling water distribution was used to supply pressurized water to the spray model sprinkler. A number of 64 graduated catch-cans with 0.16 m diameter and 0.2m height were used. The cans were arranged in eight radial legs with a distance of 1m apart. The system was run for one hour then the caught volumes were measured manually using a graduated cylinder with a capacity of 500 mL. The catch-cans data were used to determine uniformity coefficients. Line graphs were used to show relationships between the parameters measured. The experiment shows that there is strong relationship between the parameters considered. It indicated that the coefficient of uniformity (CU) and distribution uniformity of lower quarter DUlq increases with increase in nozzle size and pressure. It also shows that the largest nozzle size and pressure within the limits of this experiment gave the best CU and (DUlq) values of 96% and 90% at 1.5m height. Lager nozzle sizes with lower pressure reduces the CU and DUlq values. It is concluded from this experiment that though pressure, nozzle size and height of application influences the uniformity of application, larger nozzle sizes accompanied by higher pressure and height of application resulted in good uniformity of application. It is therefore imperative that while operating Pivot Sprinkler systems, careful selection of nozzle diameters, operating pressure and drop tube heights, sprinkler can be used to apply the ideal amount of irrigation water needed to refill the crop root zone that can neither cause runoff nor harm the crop and also provide the best uniformity possible under the prevailing wind and management conditions.

Permeability Characteristics of Improved Loess and Prediction Method for Permeability Coefficient

Due to its unique geotechnical properties, loess presents itself as a cost-effective and energy-efficient material for engineering construction, aiding in cost reduction and environmental sustainability. However, to meet engineering specifications, loess often requires enhancement. Evaluating its permeability properties holds significant importance for employing improved loess for construction materials in landfills and artificial water bodies. This study investigates the influence of dry densities, grain size characteristics, grain size distribution, and admixture contents and types on the permeability of improved loess, focusing on the Malan and Lishi loess. The falling head permeability test was conducted to analyze how each factor affects the permeability of the improved loess. The findings indicate that the permeability coefficient decreases with increased dry density and admixture content. Conversely, it demonstrates a linear increase with the average grain size (d50), restricted grain size (d60), and the product of the coefficient of uniformity and coefficient of curvature (Cu × Cc). The primary influencing factor is the type of admixture, followed by Cc and d60. Furthermore, this study developed a predictive model for permeability using a support vector machine (SVM), surpassing the predictive accuracy of linear regression and neural network models. The model provides a robust prediction for the permeability of superior loess material.

On the Influencing Factors of Non-asphalt Originated Rutting in Flexible Pavements

Rutting can substantially impact pavement serviceability and driving safety. Since most of the permanent deformation develops in the unbound layers beneath the asphalt course, the focus should be on these layers. In this research, rut depths were calculated and analyzed using the high-cycle accumulation model, where the resilient response and cyclic strain amplitude were determined through finite element analysis. Consequently, settlement depression curves were described for various subgrades and cross-sections. It was observed that grain size distribution, particularly the uniformity coefficient, plays a decisive role in rutting depth. Analysis of the relationship between settlements and axle loads indicates that the calculated settlements demonstrate a linear increase relative to the axle load. For various axle loads, the number of axle passes required to induce an equivalent settlement to the standard axle was established. The possibility to reduce the depth of ruts by increasing the thickness of the subbase was also investigated. It was found that the predicted rutting is highly influenced by the particle shape (angular, rounded, or mixed material) of the subbase. It was found that the primary portion of permanent deformations occurs within the subgrade.

Cement slurry penetration behavior of swirl grouting technology

Traditional pressure grouting technology operates under steady pressure conditions, causing the grout to easily flow along preferential pathways. This results in uneven grout penetration and increased economic costs. This study proposes swirl grouting technology, which effectively improves this problem. To verify the effectiveness of swirl grouting, a fan-shaped blade tool was also proposed. The grout penetration performance was investigated through experimental studies. The length, width, height, weight, and uniformity of the grouted bodies produced by the swirl grouting method were compared with those produced by the steady pressure grouting method. Then, the mechanisms of swirl grouting were analyzed through transparent disc visualization experiments. The results demonstrated that, at different water–cement ratios, the swirl device increased the penetration length in the X, Y, and Z directions by 43.3%, 27.8%, and 45.8%, respectively, compared to the conventional straight device, and by 57.3%, 39.4%, and 55.6%, respectively, compared to the fan blade device. Moreover, the swirl device increased the weight of the grouted stone body by 54.9% compared to the conventional straight device and by 91.0% compared to the fan blade device, significantly enhancing filling efficiency. The uniformity coefficient of the swirl device permeation decreased by 56.6% and 51.0%, respectively, compared to the conventional straight device and the fan blade device, resulting in a more uniform grout distribution. The transparent disc visualization experiment further revealed the advantage of the swirl device in promoting the migration of fine particles, with a significant increase in average penetration distance and a penetration shape closer to a regular circle. The rotating flow path of the swirl device imparts additional rotational momentum and multidirectional penetration capabilities. The resulting turbulence accelerates the mixing of grout with the soil matrix, facilitating the migration of fine particles, expanding flow channels, and reducing flow resistance. This combination of effects enhances penetration efficiency and reduces energy loss. This study offers significant practical application value for improving engineering quality, construction efficiency, and reducing costs.

Impact of initial gradation on compaction characteristics and particle crushing behavior of gravel under dynamic loading

Gravel is a widely used construction material due to its versatility and cost-effectiveness. However, gravel particles are prone to crushing under dynamic loading, causing changes in gradation. The evolution of gradation and its effects on physical properties are not well understood. This study investigates the physical properties of gravel, such as dry density, void ratio, and relative crushing index, under different initial gradations (uniformity coefficient, Cu), using surface vibration compaction tests. A hyperbolic relationship was established between initial Cu and dry density, showing that an increase in Cu can result in a decrease in the void ratio and an increase in the coordination number until stabilization. Particle crushing increases with higher initial Cu, correlating quantitatively with relative crushing indexes. Maximum dry density, minimum void ratio, and fractal dimension also correlate with these relative crushing indexes, suggesting intrinsic relationships among these properties and particle crushing. The size effect can be eliminated by establishing empirical relationships between crushing parameter and particle size.